Slope Instrumentation and Development of a Landslide Warning System
Dr. Phillip Ooi obtained a five year (2014-2019) project from the Hawaii Department of Transportation and the Federal Highway Administration (about $530,000) to develop a site-specific landslide warning system for a slope on Kalanianaole Highway, Oahu.
Landslides and other mass movement of geomaterials cause approximately 25 to 50 deaths and US $1 – 2 billion worth of damage in the United States annually. The island of Oahu, Hawaii has experienced numerous landslides along the state highways and elsewhere especially during downpours. The landslide warning system includes:
- A geotechnical investigation to characterize the soil;
- Monitoring of the in situ soil suction, water content, slope movement and rainfall;
- A saturated-unsaturated transient flow model to estimate the change in effective stresses during rain events; and
- An appropriate model for prediction and real time warning of rainfall-induced landslides
Bio-mediated and bio-inspired geotechnics in coastal applications
Dr. Ningjun Jiang is using intramural funds to investigate bio-mediated and bio-inspired geotechnics in coastal applications.
Resilient and natural-based approaches are being sought to mitigate various coastal hazards such as flooding, erosion and saltwater intrusion. Bio-cementation, as an effective method for soil improvement, has the potential to stabilize erodible and permeable coastal sands. Bio-cementation can be triggered via various naturally microbial processes such as ureolysis, denitrification, and sulfate reduction. Attempts are made to stimulate ureolytic, denitrifying, and sulfate-reduction bacteria in coastal sands on the Hawaiian Islands. The favorable conditions for each microbial process are identified in terms of enrichment media and oxygen availability. Engineering solutions are then designed based on these bio-cementation processes to address specific coastal hazards.